Martin



(n Model GUILBERT-JMARTIN.

GLASS TUBE FOR WATER GAGES.

No. 332,920. Paten ted Dec. 22, 1-885. 7

WITNiISES v ATTORNEYS.

UNITED STATES.

PATENT OFFICE.

AUGUSTE GUILBERT-MARTIN, OF ST. DENIS, FRANCE.

GLASS TUBE FOR WATER-GAGES.

SPECIFICATION forming part of Letters Patent No. 332,920, dated December 22, 1885.

' Application filed November 25, 1884. Serial No. 148,818. (No model.) Patented in France October 1, 1883, No. 157,799; in Belgium October 16, 1883, No. 62,898; in England October 17, 1883, No. 4,960; in Germany October 22, 1883, No. 26,920, and in Italy September in Glass Gage-Tubes, of which the following is a full, clear, and exact description.

The object of my invention is to provide certain new and useful improvements in glass gage-tubessuch as steam-boiler gage, thermometer, and barometer tubes, &c.-whereby the upper end of the column-of liquid can be more easily distinguished.

The invention consists in a glass tube in which a colored longitudinal strip is arranged in front of a white or other bright strip.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a face view of my improved glass gage-tube. Fig. 2 is a longitudinal sectional elevation of the same. Fig. 3 is a sectional plan'view of the same, on the line 00 at, Fig. 1.

In the glass tube A a strip, B, of white or other bright enamel, is incorporated, the width of the said strip preferably being about onesixth of the circumference of the tube, and preferably the said strip is arranged on the outer surface of the tube, as shown. In front of the said white or bright enamel strip B a colored enamel strip, D, is arranged on the middle of the same, the colored strip D being very much narrower than the white strip, so that it will show very distinctly on the same.

I prefer to make the strip D red. The bright or white strip B acts as a reflector, thus showing the colored strip more distinctly. The water 0 in the tube acts as a lens and magnifies that part of the colored strip below the level of the water, so that the part of strip D below the level of the water appears broader than the part above it, and thus a break appears on the width of the colored strip at the level of the water, whereby the level of the water can be discovered more readily, especially when the water is not clear;

, In case the liquid is not transparentfor instance, such as mercury, colored water, or alcoholthat part of the strip D below the level of the water is covered and concealed, and only the part above the level of the water is visible, and thus the level of the water coincides with the bottom of the visible part of the colored strip D. I preferto make the strips B D of enamel, but may make them of any suitable material.

The tube must at all times be so arranged that the strips will be on that side opposite the one facing the observer.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. As an improved article of manufacture, a glass gage or thermometer-tube having a colored strip arranged on and narrower than a bright strip, substantially as herein shown and described.

2. A glass gage or thermometertube provided with alongitudinal colored strip or stripe on a white or bright strip, the colored strip being arranged nearer the inner surface of the tube than the white or bright strip, substantially as herein shown and described.

AUGUSTE GUILBERT-MAR'IIN.

Witnesses:

RoBT. M. HooPER, EDWIN AGosTURIt. 

